DbVisualizer has a fixed amount of memory available, and things may go bad if you load so much data that you're getting close to this limit. The most common effect is that the GUI becomes very unresponsive or freezes completely.

To minimize the risk of this happening, DbVisualizer keeps track of the memory usage when you load tables or files and similar tasks that consume memory. If you're getting so close to the limit that problems are likely to begin to show, all memory consuming background tasks are suspended and the High Memory Usage window pops up.

All open tabs are listed along with an estimate for how much memory each tab uses. All background tasks are also shown. You need to resolve the high memory usage problem before you can continue working with DbVisualizer. Click on the red cross next to tabs that use lots of memory to close them and stop tasks that consume memory.

When you have released enough memory to get below the critical level, the icon in the Continue button changes to a green checkmark. Click it to close the window and continue to work.

If you often see this window, first consider using features that minimizes the memory usage, such as using the @run command to execute your script and the @export command to write query results to a file. As a last resort, you can increase the amount of memory DbVisualizer can use. Please see the FAQ page on our web site for how to do so.

In rare cases, closing tabs and stopping tasks do not release enough memory to continue, possibly due to memory leaks in the DbVisualizer code. If this happens, you can click the Create Heap Dump button. The heap dump file is named heap.bin and stored in the preferences folder, typically the .dbvis folder in your home folder. It may help us find memory leaks and fix them, so please send it to us with a description of what you were doing when you ran into this problem. The file can be huge, so please compress it (e.g. using the zip command) before mailing it to us.

If you cannot release enough memory to continue, you can use the Shutdown DbVisualizer button to shut down and start fresh.